In known toggle-lever power amplifiers of this kind, the toggle levers are connected together and the toggle levers with abutment and pressure blocks are also connected together by joints. These toggle-lever power amplifiers have the disadvantage of expensive construction, while in addition the sliding friction occurring in all the aforesaid toggle-lever power amplifiers causes considerable wear, particularly in the case of compact construction of such a power amplifier with which high compressive forces are produced. With these prior toggle-lever power amplifiers, where the overall dimensions are small such as those fitted for example in the hollow spindles of machine vises only comparatively low compressive forces are produced.
The problem underlying the invention, in addition to eliminating the aforesaid disadvantages, is to provide a toggle-lever power amplifier of simple construction having exceptionally low wear, i.e. a very long life and which, in addition, although of small, compact construction, permits the production of very high compressive forces.
In a toggle-lever power amplifier according to the invention this problem is solved in that the two toggle-levers are supported directly on each other and also on abutment and pressure block, and all supporting surfaces are so formed that the co-operating supporting surfaces roll on each other with line contact during the movement of the toggle lever pair.
In this novel toggle-lever power amplifier, the above-mentioned joints and the accompanying sliding friction resulting in wear are non-existant. Since the supporting surfaces of the two toggle levers roll on each other and in the same manner the toggle levers also roll on pressure block and abutment, practically no wear occurs in these parts and in addition very high compressive forces can be produced without detrimental wear, even in the case of small, compact construction.